Most states have statutes that provide that a mortgage or deed of trust may be partially discharged or released in the county land records by the recorder of deeds. Generally these statutes proved that a certificate must be filed with said recorder and executed by the mortgagee or on its behalf and acknowledged as prescribed by law.
This form is a generic example that may be referred to when preparing such a form for your particular state. It is for illustrative purposes only. Local laws should be consulted to determine any specific requirements for such a form in a particular jurisdiction.